The former Boston Red Sox legend had a lot of high praise for Martinez — and how could he not? The slugger leads the league in home runs (34) and RBIs (98) while toting a .328 batting average. He’s made an instant impact since joining Boston in the offseason, and it certainly has caught Ortiz’s attention.

“What he’s doing right now, I’m not surprised about what I’m seeing,” Ortiz said on WEEI’s “Ordway, Merloni & Fauria on Wednesday. “I noticed that in spring training. I saw him for about three or four days hitting batting practice every day. I walked out of that field like I just saw a ghost. That’s how impressed I was.

“He just wants to get better every day,” Ortiz continued. “This is a guy who will go and hit batting practice after the game. Who the hell does that? (He’s) not playing around.”

Aside from consistently trying to improve his game at the plate, Martinez also has helped his teammates with their swings — most notably Jackie Bradley Jr. and Rafael Devers. And Ortiz said having a guy like Martinez in the clubhouse can help everybody on the team.

“I believe he’s just getting everybody around him better,” Ortiz told OMF. “If you see the big dog going at it like that, the rest of the squad, you know what they’re going to do. ‘I’ve got to get better, too.’”

Big Papi compared the leadership role Martinez plays and the way younger players look up to him to that of Nomar Garciaparra, Manny Ramirez and Jason Varitek.

“They want to find out why a superstar is a superstar,” Ortiz said. “Smart players, that’s what they do. They be like, ‘J.D. Martinez, he’s the best hitter in the game right now. Let me see why he’s so good.’ That’s how you approach the game, you don’t waste your time. In the clubhouse, guys aren’t trying to waste their time. They’re trying to get better. … That has been the culture of this clubhouse.”

The results have been clear, as the Red Sox lead Major League Baseball with 81 wins. And while Martinez’s production has been a big part of that, so has the way he’s had an impact on his teammates.